Re: [PATCH v18 18/23] KVM: arm64: CCA: Mandate VGIC_V3 for Realms

[Fuad Tabba]

Hi Suzuki,

On Tue, 15 Sep 2026 17:01:36 +0100, Suzuki K Poulose
<suzuki.poulose@xxxxxxx> wrote:
[...]
> diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
[...]
> @@ -84,6 +84,9 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
>                  !kvm_vgic_global_state.can_emulate_gicv2)
>                  return -ENODEV;
>
> +        /* Realms only support VGIC_V3 */
> +        if (kvm_vm_is_realm(kvm) && type != KVM_DEV_TYPE_ARM_VGIC_V3)
> +                return -ENODEV;

Could this be kvm_vm_hyp_is_distrusting(kvm) (with patch 13's compare
as >=) rather than a Realm-only check? A GICv2 isn't possible under
pKVM either, but there the v2 mapping is only rejected later, in
kvm_vgic_map_resources() at the first run; this would give both the
same -ENODEV at KVM_CREATE_DEVICE.

Cheers,
/fuad